The Kolaati were a group from the Delta Quadrant. Wixiban described them as being "mean as fire snakes."

Kolaati traders made a fortune trafficking in narcotics on Bahrat's space station near the Nekrit Expanse. Bahrat was unaware of this, as they masked their activities by disabling his surveillance systems, masking his sensors, and creating false visual signals on a nearly nightly basis.

In the 2373, a destitute Wixiban tried to trade narcotics with Kolaati traders near the Nekrit Expanse, one of his most important contacts being Tosin. Eventually, Neelix convinced him to help trading outpost owner Bahrat arrest the Kolaati. (VOY: "Fair Trade")

The term Kolaati might not have refered to a species, as Tosin's associates were not of the same species as him.